Since several years already, various types of pumps or micropumps for medical use are known. The so-called portable micropumps are particularly appreciated in the therapeutic treatment of patients such as those suffering from diabetes or cancer, who must receive permanently, or at least during extended periods of time, a controlled dose of a medicamentous substance administered continuously. The so-called peristaltic pumps or micropumps have been developed for such a use and are described in the specialized literature.
The patent application FR-A-89 04044 describes such a type of micropump. The same includes two separate modules, the so-called "motor" module which cannot be sterilized and which includes the motor and its control circuitry and the so-called "pump" module itself which can be sterilized and which includes a rotor provided with rollers, a tube and a pressing device cooperating with the rollers for pressing flat said tube. These two modules are assembled in a reversible manner.
The patent application EP-A 447 909 describes a model of a similar micropump, of which one main feature is the irreversible assembling of a "container" module and of a "motor" module. This micropump model further includes various safety systems which assist in ensuring asepsis during administration of the medicamentous solution to the patient, as well as in preventing any operating error by the patient himself. As illustrated in EP-A 0 447 909, the module including the container intended for the medicamentous solution has as a characteristic feature of the micropump, a filling orifice accessible to the user when the two modules are separated, but which is thereafter inaccessible to said user when said modules are assembled irreversibly. Subsequent access to the medicamentous solution is thus totally prevented, as well as any later contamination of this solution after it has been filled in a sterile manner into the storage container and this during the whole period of functioning of the micropump.
Although practice shows that this type of safety fulfils perfectly well its role once the micropump is in operation, the problem still remains of maintaining asepsis during the extemporaneous filling of the "container" module. The filling of such a module poses no real problem in a hospital environment, where trained staff and appropriate installations are available, such as for example a laminar flow hood or clean room; however, the filling by the patient himself, who cannot be expected to have the skill required, is another matter when a complete asepsis must be maintained during this operation and any accidental contamination of the medicamentous solution must be avoided. The invention provides a solution, which is new, original and technically reliable, to the problem described above.